1. Field of the Invention
This invention relates generally to IP based communications for emergency 911 services. More particularly, it relates to emergency alert (e.g., Emergency Alert™ type services) and technology for land-based and/or wireless phones, including and particularly Voice Over Internet Protocol (VoIP) phones.
2. Background of Related Art
Many communities have, or are in the process of, implementing what is known as an emergency alert system. An emergency alert system allows an emergency center to rapidly notify by telephone residents and businesses within a given geographical area affected by any given emergency. The larger the emergency, the larger the affected community and number of telephones to be notified. Public safety access points (PSAPs) typically employ emergency alert in emergency situations where it is necessary to contact thousands of citizens to alert them of pending or potential dangers, such as neighborhood evacuations, tornado warnings, etc.
FIG. 4 shows a conventional emergency alert system for implementing reverse 911.
In particular, the conventional emergency alert system 400 for implementing reverse 911 includes a dialing controller 420, a phone number database 410, a modem bank 430, and a plurality of users 440. Generally speaking, as shown in FIG. 4, there are a given number of phone numbers 1 through Z to be called using a smaller number N of modems in the modem bank 430.
Current emergency alert systems 400 employ banks of telephone dialers (e.g., modem bank 430 for dialing out) to quickly work through a list of hundreds, and even thousands (or more) of telephone numbers associated with users 440, playing an audio recording to each answered phone. Some emergency alert systems 400 will leave an emergency message on an answering machine if that is what answers the line. Emergency alert systems 400 will keep track of which telephone numbers in a list from phone number database 410 that are not answered after a predetermined number of rings, and will attempt to redial those phone numbers a predetermined number of times in an attempt to make contact with a user 440.
Currently, banks of outdialing “phones”, i.e., modem bank 430, are used to implement reverse 911. This type of service is used to notify people in a local area of an emergency event such as a Tornado, chemical spill, terrorist attack, etc. The bank of phones from modem bank 430 dial specific phone numbers, play a prerecorded message, disconnect and then dial the next number in a sequence of provisioned numbers meeting a specific criteria from phone number database 410.
But the present inventor has appreciated that the current approach to reverse 911 relying on such an emergency alert system 400 may be slow to complete if an exceedingly large number of phones must be called through a proportionately small number of modems since each phone, associated with respective users 440, is individually dialed and the complete transaction must be executed before moving on to the next number. The number of simultaneous calls that can be completed is limited to the number of modems because each executes a single phone call at a time.
There is a need for a better emergency alert system capable of quickly and reliably alerting phones currently within a region affected by a given emergency message.